Population genetic structure of Zeugodacus tau species complex in Thailand

Abstract

© 2019 The Royal Entomological Society The tephritid fruit fly Zeugodacus tau is a serious agriculture pest, especially of cucurbits in Thailand, where it is classified as a complex species of nine siblings (Z. tau A, B, C, D, E, F, G, I and J). Based on single-strand conformation polymorphism (SSCP) analysis, 33 distinct mitochondrial cytochrome c oxidase subunit I (mtCOI) haplotypes were found in three sibling species, Z. tau A, C and J, in Thailand. Genetic structure analysis of the population revealed relatively large genetic differences among these sibling species, reflecting a tendency toward speciation. The maximum likelihood tree and median-joining network reconstructed from the mtCOI sequences of 33 haplotypes supported the separation of these three sibling species within the Z. tau complex. The three-level hierarchical analysis of molecular variance based on geographical regions and the Mantel test for isolation-by-distance showed significant genetic structuring of the Z. tau complex in Thailand. However, the genetic differentiation among geographical groups was rather low, which may be reasonably explained by natural and human mediated dispersal, as well as host associated differentiation. The SSCP analysis on the population genetic structure of Z. tau species complex in the present study should benefit pest management.